[Xapian-discuss] Xapian JNI questions

[Alex Kushkuley]

I am using Xapian JNI layer for a while and I am interested in
status of Xapian JNI, documentation, bug lists, references, etc.

Specifically,  is the following correct:
1)  Writable database object must be finalized to release writable
database lock (otherwise database could  become unreadable if
application is restarted (after crash ) ?

2)  finalize method must be called  on any Xapian JNI onject when its
no longer needed ?


I have also encountered  a few bugs

3) the following function in org.xapian.ESetIterator  always returns false.

 public boolean hasNext() {
       try {
           return XapianJNI.esetiterator_equals(id, _end_id);
       } catch (XapianError xe) {
           throw new XapianRuntimeError(xe);


When changed to

 public boolean hasNext() {
       try {
           return !XapianJNI.esetiterator_equals(id, _end_id);
       } catch (XapianError xe) {
           throw new XapianRuntimeError(xe);
       }
   }

it seems to be working correctly.



4) Attempts to use MatchDecider caused an exception:

 Exception in thread "Thread-37" java.lang. accept
       at org.xapian.XapianJNI.enquire_register_match_decider(Native Method)
       at org.xapian.Enquire.registerMatchDecider(Enquire.java:127)
       at tv.cozmo.neo.logic.search.YouTubeShowIndexManager.isIndexed(YouTubeShowIndexManager.java:286


The JNI code is as follows:

       JavaMatchDecider(JNIEnv *xenv, jclass xclazz, jobject &obj) :
MatchDecider() {
           env = xenv;
           clazz = xclazz;
           _obj = obj;
           TRY
               _deciderclass = env->GetObjectClass(obj);
               if (!_deciderclass) goto on_error;

               _acceptmethod = env->GetMethodID(_deciderclass,
"accept", "(Lorg/xapian/Document;)I");
               if (!_acceptmethod) goto on_error;

on_error:
           CATCH(;)
       }

Since the return type for accept method is boolean, I have replaced
"(Lorg/xapian/Document;)I" with "(Lorg/xapian/Document;)Z" ( and the
same for JavaExpandDecider ).

With this change the NoSuchMethodError exception is no longer thrown,
however, it looks like
the JavaMatchDecider is not called at all.



Regards & Thanks,

Alex Kushkuley